
Boost Users : 
From: Shriramana Sharma (samjnaa_at_[hidden])
Date: 20210129 15:54:31
On Thu, Jan 28, 2021 at 10:11 PM Shriramana Sharma <samjnaa_at_[hidden]> wrote:
>
> On Thu, Jan 28, 2021 at 5:57 PM Shriramana Sharma <samjnaa_at_[hidden]> wrote:
> >
> > https://github.com/boostorg/math/blob/develop/include/boost/math/tools/toms748_solve.hpp#L352
> >
> > Can you elucidate which step from the original paper this quadratic
> > step corresponds to?
>
> On more careful examination I see that 4.1.3 and 4.2.3 of the original
> paper have a n == 2 option, which would lead to a compulsory quadratic
> evaluation.
But still as per the paper, the step after such a compulsory quadratic
step would branch into a quadratic_interpolate with count = 3, but in
this implementation such a step is missed. I have no idea whether this
will lead to inaccuracy, since further steps would definitely refine
the bracket, but just placing this on record here.
I was also thrown a bit by the redefinition of max_iter as â€œThe
maximum number of function invocations to perform in the search for
the rootâ€. To my understanding an iteration is defined by the loop in
the algorithm, and the paper speaks of â€œ3 or 4 function evaluations
per iterationâ€. I realize I'm quibbling at semantics, and one may be
free to either limit the number of iterations or function calls
(mostly the former is done I think) but it may be better to rename the
variable to max_funcalls or such to clarify its purpose and highlight
the deviation from the original paper.
Thanks, and please do respond when you can.
 Shriramana Sharma à®¶à¯à®°à¯€à®°à®®à®£à®¶à®°à¯à®®à®¾ à¤¶à¥à¤°à¥€à¤°à¤®à¤£à¤¶à¤°à¥à¤®à¤¾ ð‘€°ð‘†ð‘€ð‘€»ð‘€ð‘€«ð‘€¡ð‘€°ð‘€ð‘†ð‘€«ð‘€¸
Boostusers list run by williamkempf at hotmail.com, kalb at libertysoft.com, bjorn.karlsson at readsoft.com, gregod at cs.rpi.edu, wekempf at cox.net